Photometer.



F. E. IVES. PHOTOMETBN APPLICATION FILED SEPT'. z'f 190s.

'Patented Mar'. 2, i909.

2 SHEETS-SHEET l.

lll/lll;

E. E. IVES. PHOTM'ETER..

AP'PLIOATION PIL-BD SEPT. 25, mos.

Fatented Mar. 2,1909.

2 SHBETS-SHEET 2.

35 relations of llillierent colors lia-vii are substantially identi-cal with those ol' said Specification of Letters Patent.

.-atented Marel?. f?, 193%.

Application :filed September 25, 1908. Serial No. 454,793.

To all whom/t 'may concern:A

Be it known that l, FREDERIC, l?. lvns, a citizen of the United States, vresiding in Woodclile-on-the-Hudson, .eelnwken, New Jersey, have invented certain llnprove ments in Photoineters, or which the following' is a specification.

The objectot my invention is to provide a convenient means Wherewith to measure the relative luminosit;7 of different sources of 'light or ol objects either transparent or opaque, and more particularly to make and record separate measurements indicatin th o relative presence or three isolated hands of spectrum color in order that thc words may indicate differences of hue as wel' as luminosity.

The device is f lesignerl to r ilv and quickly measure, without preti f' arljustnient for personal color eque-.tirar 1jr-qualit5T of illumination, all tin-ts or hues having' smoothly graduated spectra, and is adapted for the ineasuren'lent of; difference in strength ol solutions or spreads ol5 color haring' the Vsaine kind of absorption spectra, thus providing; for the standardizing of dyes, paints, etc., of definite composition., or for measure ing the hues of water, oils, beers, l'iaper pulps, and the like. The instrument loes not take into account intermediate port-ions of the spectra of 'thc object colors and ccnscinlcntly the records (lo not ilitlicart with the saule precision as in the color meier forro.. subject of my prior patent No. Sill-.L Y., 'li'lwcntly constitutcd brel-:en or handed spectra, hut where, the tints are light, and the spectra or the colors snmothly graduated the records prior patented tlc/'vice anfl tac elimination of preliminary .fnljustinents lor personal color equation and quality' ol illm'nination reduces the nul'nhc" .nl Factors thatliave to he corfli nated, wl' Y the dille/rence ol" procedure rcsulting from the inaliing; of separate measA ureincnts for difieren t parts ol the color sow tra and the .Greater simplicity ol" cons rw and @eration of the device renale-1' it convenient 'for use in those cases to Fluch i is adapted.

ln the accompanying: lrawirigs-ligure l is a horizon tal longitlulinal section of my iin* proved instrument; Fin'. 2 is :l side elevation of the saine; Fig'. l is a tor or plan ric and Fig. Ll is an elevation of the liront eli-:l or the :instrumen i whereby, ef'heil the ln'the drawing, l'represents the main casf ing' of the instrument 'which may be oil any suitable material and. of rectangular' or other shape in cross section, 2 representing' the 60 eye-piece tube and x the position of the oye in making' observations. At the end of the (ej/apiece tube is a segmental plate 3 with. central aperture -l and mounted so as to swing across this aperture is a carrier 5 con- 65 taining -blue, green and red. color screens, indicated resiiectively at B, G and l, theo color screens being identical with those used. in my previously 'patented color meter. The color screen carrier is, in the present in- 7@ stance, secured to an arm o' proterl upon the top of the casing l 7. ln the front end ol the casing' l arc vertical it apertures w and w, the area of the aperture w being susceptible of variation oy movement or' 75 vertically sliding' 'rerlge-sl'iape l shutter Q in respect to a lined plato lt). The shutter 9 hears awainst a lined averse 1l on the front of the casing;y and is lielll in contact therewith by means ol' a 2 'ing' lf?, another spring i3 3@ serving' to keep it in contact ith the liront end of the casing' l. The area of the ape-r ture 'w' can he varied hy means of laterally adjustable shutters lst and l5. the shutter le; being; carried hy an arni 16 locatefl at one 55 side or the casing' l and pivotcrl thereto at and the shutter heine; carried by av lever lll, pivotal, 29, to 'the top ofthe casing l.

Adapted to an opening; in the arm l@ go micrometer screw 2l in 'chiel'. is torinel Si threaded opening' tor the reception of another screw 22, the lat-ter hearing.; against a 'pla-to on tho side of the casing l, shown in Fig. il. The nlicroinetcr screw .11 carries 95 a pointer 2 whichoperates in connection with a graduated sca i casing, and the arp projecting lun' 26 wli miro upon 1.() near lune rear rg u' of the saine, a hearinv upon the front nor-len or the lei, e

"Hicroine "r moved in one direct on, the shut l5 will he siznultanecusl one another, and, wljien sain'. in the opposite rlirecticrn u slru'rrers he simultaneously moved e. other, cpansion or contraction of i el the aperture 1e heir@ l ellected. T

zerosrijark 'of the scale the adjoining edges of the shutters 14 and 15 will be in contact with one another and the aperture w will be com letely closed.

T e casing 1 contains a plano-convex `field lens 30 and a plano-convex lens 3l for focusing the 'iield upon. the eye of the observer at x, the aperture w being in the axial line of the lens 30, and the aperture w beinglaterally displaced in respect to said axis. A rhomboidal prism 32 covers one-half of the area of the-field lens 3() and serves to divide the iield and divert the rays of light l from the aperture fw into vthat half of the lens which the prism covers, the prism being.

so calculated that, by retardation of the light waves through the body of glass, the optical distance from the rield lens direct to side. vlf a wedge prism 35 be placed over the aperture w it will bring into the respective half of the vl'ield an object suitably placed at one side of the white back round, and if tlie'shutters 1.4 and 15 are t en adjusted by the micrometer screw 22 until the two halves of the field exactly match, the reading on the scale will indicate the luminosity of the object relatively to the opal glass background. lt the two halves oli' the 'i'ield appear different in hue separate measurements should be taken successively through the red, green. and blue-violet screens R, G and B, and the triplicrie record will then indicate diiteronce of hue at well as luminosity.

rlhe accurate matching of the two halves of the iield is made possible by using color screens transmitting narrow, isolated bands of the spectrum, as otherwise `there would sometimes be a marked diilerence in the hue ot the two halves oi' the iield. It is for this i purpose particularly, altnough also to make the readings. interchangeable in some kinds ol work with those obtained by'a color meter of the character set forth in my previous patent, that the color screens used 'are identical in character with those used in said patented device.

Transparent objects, or solutions contained in transparent tanks, may be measured l'by placing them in the position of the prism, spring clip 37 being used for alholder 36 with this purpose. Adaptation to the comparison of different sources of illumination involves only suoli arrangements as are familiar to all experts inV photometry.

claimt# 1. The combination, in a photometer, of va casing having two light-receiving apertures,A

4means for varying t e area oi one of said apertures, a field lens positioned to receive upon one portion the light rays from one of said'a ertures, and means for directing upon 'the 'other portion of the lens the light rays from the other aperture.

2. vThe combination, in a photometer, .of a casing having two light-receiving apertures, means for varying the area of one of said apertures, a 'field lens positioned to receive upon one portion the light raysvfrom one of said apertures, means for directing upon the other portion of the lens the light rays from the other aperture, and a lens for focusing said field upon the eye.

casing having twolight-receiving apertures, means for varying the area of one of said apertures, a iield lens'positioned to receive upon one portion the light rays from one of said apertures means for directing upon the other ortion of the lens the light rays from the ot er aperture, andthree color screens susceptible of beihg interposed successively in the path of the transmitted light rays.

4. The combination, in a photometer, of a l casing having two light-receivmg apertures, l means for varying the area of one'of said l l l apertures, a Afield lens positioned to' receive upon one -portion the light rays from. one of said apertures, means for directing upon the other portion of the lens the light rays from l the other aperture, a lens Jfor focusing said 'i 'lield upon the eye, and three color screens susceptible of being interposed successively The combination, in a photometer, of a 5.l The combination, in a pliotoineter, of a casing having two iigl'it-.reeeiving apertures,

l betwmr; said focusing lens and the eye. l

means roi' varying the area of one ol said apertures, a measuring 'scale cooperating with said means, a iicld lens positioned to receive upon one portion the light rays from one of said apertures, and `means for directlight rays from the other-aperture..

6. The combination, in a photometer, of a casing having two light-receiving apertures, l means for varying the area of one of said l apertures, a measuring scale cooperating l with said means, a field lens positioned to rei ceive upon one portion the light rays from l one ol. said. apertures, means for directing l upon the other portion of the lens the light rays from the other aperture, and a lens for l focusing said field upon the eye.

7. vThe combination, in a photometer, .of a `casing having two light-receiving apertures, means for varying the area of one of said apertures, a measuring scale cooperating ing upon the other portion or' the zcns the with said means, a iield lens positioned to re ceive upon one portion the vlight rays from one of said apertures, means for directing upon the other portion ol the lens the light rays from the other aperture, and three color screens susceptible of being interposed. successively in the path of the transmittedlight rays.

8. The combination, in a photometer, of a casing having two light-receiving a ertures, means forl varying the area of one o said apertures, a measuring scale cooperating with said means, a field lens positioned to receive upon one portion the light rays from one Y.of said apertures, means for directing the light rays fromthe other aperture upon the other ortion of the lens, a lens for focusing said 'ield upon the eye,. and three color screens susceptible of being-interposed successively between the said focusing lens and the eye.

9. -The combination, in a photometer, of a casing having two light-receiving apertures, means for varying the area of one ol said ap# ertui'es, a 'ii'eld lens, and a rlioinboidal prism partially covering said lield'lens and through which the rays of light from one of the lightreceiving apertures are caused to pass.

l0. The combination, in a photometer, of a casing containing a iield lens and liaving two light-receiving apertures, .one of which is'laterally displaced 1n respect to the aXis of the lens, and a rlioniboidal prism partially covering said lens, through which prism 'the rays ot' light from said laterallyT displaced ape erture are caused. to pass, said p'rism being so calculated as to render the optical focus of the laterally displaced aperture the sanie as .that of the other aperture.

ll.. The con'ihination, in a photometer, ol` a easing having two light-receiving apertures, ,means for varying the area of one of said apertures, a iield lens positioned to receive upon oney portion the'light rays from one of said apertures, means for: directing upon the other portion of the lens the light rays from thec'itheiV aperture, three color screens, disposed side by side, and a swinging carrier whereby'said screens are susceptiblev ot' being interposed successively in the path of the transmitted light rays.

i2. The combination, in a photometer, of a casing having two light-receiving apertures, means for varying the area of one oi' said. apertures, a field lens positioned kto ren ceive upon one portion the light rays from one of said apertures, means lor directing i upon the other portionof the lens the light rays from the other a erture, a lens for focusing said iield .upont e'A eye, and a swinging carrier interposed between said focusing lens and the eye, and provided with three color screens disposed side by side.

13. The combinatlon, in a photometer, of

a easing having at one end two light-receivf `means for directing upon the other portion of the lens the rays of light from the other aperture, three color screens, and a swinging carrier whereby saidy screens can be interposed successively in the path of the transmitted light rays.

144. The combination, in a photometer, of

a casing having two light-receiving aper-` tures, means for varying the area of each -of sald apertures, a ield lens positioned to lreceive upon one portion the light rays from one of said apertures, and means for' directe ing upon the'other portion of the lens the light rays from the otner aperture.

15'. flhe combination, in a-photometer, of.

4a casing-having two .light-receivingapertures, a pair of shutters movable from and toward eachI other forvaryingjthe area of' one of said apertures, a field lens positioned to receive upon one portion the light rays from one .oi said apertures, and means for directing upon the other portion of the lensv the light rays from the other aperture.

16. The combination, in a photemeter,A of a casing having 'a light-receivingA aperture, a pair of shutters for regulating the area-of said aperture, pivoted carriers for said shutters, and means whereby the movement olione ot' said carriers is ltransmitted to the other in order to effect the simultaneous movement of thershutters.-

y17. The combination, in a photometer, of 'a casing having a light-receiving aperture,

shutter for varying thearea of said aperture,

a shutter-carrying arm, an adjusting screw engaging said arm, and a setting screw carried by said adjusting screw.

in' testimony whereof, I have signed my naine to this specification, in the presence of two subscribing witnesses.l p FREDERIC E. yYVES. 'Witnessesz GEO. MACLEAN, TREADWELL CLEVELAND. 

